Luminaire



April 20, 1948. w. G. DARLEY LUMINAIRE Filed April 27, 1945 FIG.|

3 Sheets-Sheet 1 INVENTDR= WILLIAM G. DARLEY,

25 WQ QW HIS ATTORNEY April 20, 1948. I w, DARLEY 2,439,885

LUMINAIRE Filed April 27, 1945 3 Sheets-Sheet 2 FIGS I NVENTOR'. v WILLIAM G. DARLEY,

HIS ATTORNEY April 20, 1948. w. G. DARLEY LUMINAIRE Filed April 27, 1945 3 Sheets-Sheet 3 INVENTQR:

o. v aw Q m WI L IAN G. DARLEY,

HIS ATTORNEY Patented Apr. 20, 1948 LUMINAIRE William G. Darley, Cleveland Heights, Ohio, assignor to General Electric Company, a corporation of New York Application April 27, 1945, Serial No. 590,617

4 Claims. 1

My invention relates to lighting equipment or luminaires and is of particular interest in connection with such equipment accommodating elongated fluorescent lamps and mounted at substantial heights above the fioor.

Maintenance of such equipment, that is, changing the lamps and cleaning the equipment is frequently neglected because of the inconvenience involved in first obtaining and then climbing up a ladder to reach the equipment. The principal object of my invention is to provide a luminaire which may be mounted at substantial heights and yet be serviced from the floor of a room. Another object of my invention is to provide such a luminaire which may be easily installed. Further objects and advantages of my invention will appear from the following detailed description of species thereof and from the appended claims.

In the drawing accompanying and forming part of this specification an embodiment of my invention is shown in which: Fig. 1 is a perspective view of a species of my new lighting equipment as seen from below; Fig. 2 is a similar view of the luminaire in position for servicing with the support covering canopy lowered to show the support; Fig. 3 is a side elevational, enlarged, partly sectional view of one of the spring balances of my equipment; Fig. 4 is an enlarged, fragmentary, side elevational, partly sectional view of one end of the supporting means and one pair of electrical contacts of my equipment; Fig. 5 is an enlarged, top plan view of a catch for releasably locking parts of my equipment together; Fig. 6 is an enlarged, fragmentary, side elevational, partly sectional view of the means for moving the fixture vertically and for looking it with the support; Fig. 7 is a side elevational view of the catch shown in Fig. 5 rotated 90 degrees from its position in Fig. 5; and Fig. 8 is an enlarged, fragmentary, side elevational, partly sectional view of one end of another species of my invention.

As shown in Figs. 1 to 4 of the drawing the lighting equipment or luminaire comprises a lighting fixture I and a ceiling mounted, enclosed support 2 for the fixture I which is attached to the support by a number of tapes 3 (Fig. 2). The fixture I is of a conventional type and comprises an elongated support housing or channel 4 enclosing the wiring and ballast equipment for fluorescent lamps supported in a horizontal plane and parallel to and on'both sides of the channel by sockets secured to the channel 4. The lamps are shielded from view by curved,

light diffusing side and end panels and by louvers mounted beneath the lamps. Such fixtures are well known and further description thereof is not necessary for a complete understanding of my invention. The lamps may be readily removed and the interior of the fixture cleaned from the top of the fixture without disturbing the shielding medium when it is lowered from its usual position adjacent the ceiling (Fig. 1) to the position in which it may be serviced near the fioor (Fig. 2).

The support 2 for the fixture is shown enclosed by a canopy 5 in Fig. 1 and in detail in Figs. 2 to 4 of the drawing and comprises a support or mounting plate 6 attached at each end by a bolt 1 (Fig. 4) to a conventional spreader 8 which may be secured to the usual ceiling outlet box inthe usual manner. The plate 6 has four counter-balances 9 attached thereto, one at each of its corners, and the tapes 3 of the balances 9 are attached to the channel 4 of the fixture I at four spaced points (Fig. 2). As shown in Fig. 3 each of the counter-balances 9 comprises a hollow drum la] mounted for rotation on a fixed shaft II secured to a housing I2 which is bolted to the support plate 6. A volute spring I3 having its inner end secured to the fixed shaft is and its outer end secured to the inner surface of the drum Iii is provided to exert torque on the drum. The torque exerted by the springs I3 in the four balances 9 is sufficient to balance the weight of the fixture I in any position of the fixture i. Thus, the fixture I may be easily moved in a vertical direction and will remain at rest in any selected position between the plate 6 and that determined by the length of the tapes 3.

I have provided means for readily moving the fixture I vertically and for positively locking it with the plate 6 while the person doing the work stands on the fioor. The means is shown in Figs. 2, 5 and 6 of the drawing and comprises a key I4 in the form of a rod of a length suitable for conveniently reaching the fixture I from the floor and a lock having a flared, tubular guide I5 (Fig. 6) which accommodates the end of the rod I4, passes through the lower wall I6 of the channel 4 and has its fiared end II spaced from and bolted to the upper channel wall l8.

The look also comprises a rotatable catch IQ ,of the butterfly type having a shouldered stem 20 passing through the upper wall l8 of the channel and extending into the guide tube l5 for engagement with the end of the rod I4. The shoulder 21 of the stem 28 rests against a washer 22 on the outside of the upper wall I8 of the channel Another washer 23 provided with a cotter pin 24 extending through a transverse opening in the stem 28 is located so as to engage the inside of the said channel wall I8. The catch I9 thus is rotatable but is not movable longitudinally.

The rod M h'asa hand-grip "25 at one end and its opposite end 26 is spade shaped to engage with a slot 21 in the stem 28 of the catch I9.

indexing .pin 2'8, adjacent its spade-shaped end 26 which slides along a longitudinally examine,

indexing slot 29 in the guide I '5 as the emit of the rod 14 is moved into the guide I5. The indexing slot 29 extends a *suficient j distance longitudinally of the guide I to permit the spade end 26 of the rod I4 to enter the stem-slot 2l The indexing slot 29 then turns at right angles and extends horizontally through an-angular distance of approximately 90 so that:the rod It and therewith the catch 'I'9 may be rotated through a. similar angular :distance to move the catch lll'from its locked position with plate 6, shown in Fig. 5, to its unlocked position in which it may pass through-thezbutterfiy shaped opening 31 in plate 6. When the catch 'I'9 isV-in its unlocked position thepin '28 is within the "horizontal :portion .of the indexing slot 29. Thefixture i may then be lowered for servicing by exerting a downward force on the rod 1-4. Afterthe fixture -I has been servicedit maybe returned to its raisedposition :bypushing the rod I4 upward and then, when the fixture I has-reached itslimit of travel upward, rotating the rod 90 to return the catch I 9 to itslockedLposition, and the .pin 28 on the rod M to aposition to ;-follow the vertical portion of the indexing slot 29. The end 26 of the rod I4 may then be withdrawn irom'theguide I5.

The butterfly catch I9 is ;-releasably held against rotation in either its engaging or disengaging positions with .plate 6 by a spring clip 32 secured to the channel wall I8 and engaging :a pair of suitably-spaced notches 33 in the,:peripheral portion of washer 22 which is keyed to stem it of catch I8 so asto rotate therewith. The catch I9 is of substantial depth or thickness and the lower surfaces 34 thereof have a helicoidal portion to pull the fixture I up against-the other parts of the luminaire as the catch I9 is rotated to engage plate 3. The surfaces 34 also have a horizontal planar portion which engages-plate 8 lamp :ballast-s in the channel'4. The contacts 35 and-33 are disengaged'and the fixture thus -disconnected from the power source whenthe '--fixture is lowered even a small distance from the support plate 6 so that it may be safely worked on in its =lowered position.

:Ea'chzmale contact :36 comprises ameta'l 'contact rod J31 'o'ne'end of which iprojects beyond a-spllt tube :38 of aelectrical' insulating material,

such .;as fibre tube, for. engagement with "the the holding tube M to the bushing 43. The lower -endof the contact rod 3'! is provided with a conyen'tional screw ll for clamping a current lead wire connected to the lamp ballast against the rod-37!.

"The female contact comprises, in addition to the :slotted part 39, a split tube 48 of electrical insulating material, such as a fiber tube. The slotted-part 39 and the split fiber tube 48 are held in a supporting tube 49 by a set screw 5=I. The supporting tube' lii has alshoulder '52 :held against thespreadert by a nut 53 engaging with the threaded endof the support tube 49 which projects through the spreader '8. Theend of the slotted contact part-39 is provided with ascrew 54 for clamping thereagainst a current leadwi-re from the :power "source. A screw .cap '55 "of electrically insulating material engages the -threa'izled end of'the holding tube '49 and :gives protection against accidental contacts withexposed portions ofthe conducting .parts of the female contact :35. A similar cap '55 is providedto protect against accidental contacts with the :end of :the contact rod :3 within the channel A.

As :is:plain1y-shown in the :drawing the parts of the contacts 35yiand 3-5 are so arranged that the contact rod 3! is withdrawn from the slotted part 391beore its exposed endireaches the :end of the holding tube 49 as the --fixture is pulled downward. Thefslotted part 38term'inates well within the holding tube 4.3 which :is too small indiameter :to permit the insertion of a person's finger. The portion of the contacts 35 and 33 whioh overlap each othe'r-when-the catch I3 is 7 locked with plate 8 do not overlap-sufiiciently to engage each *other when the catch I9 is below plate *6. Thus; if the catch -I9 is rotated inadvertently so'that itrest-s against the'bottom of plate 6 the cont-acts 35and-33 do not engage each other and the lamps will not light. The failure of'the iam'ps-to light will cause-the operator to investigate and thus "discoverhis mistake.

"The "canopy 5 is secured to the supporting plate by bolts5'8,'one1of"whichisishown in Figs-4 of the drawing. The canopy 5 has open ngs through which extend the supportingta'pes 3 and through-which ma pass the male contacts 38 and the catch I9. The tapes '3 are "fastened to the channel l by easily releasable-bolts '5! engaging with eyes 58 attached to the tapes.

The equipment is easily installed as follows: The spreader 8, to which. is attached the "female contacts .35, the supportingplate .6 and its .halances 9, is fastened in the usual manner to the ceiling fixture stud. The wires from thefoutlet box are :connected to the female contactsfldand the canopy -5.is.-bolted to thesuppor-t -plate 8 to conceal the supporting and electrically conducting parts. The tapes -3-are then pulled downone at -a time and bolted .to the fixture channel 3. The fixture is'then raised'toits at rest position against 'the "canopy '5 and the butterfly catch 19 is turned to its locked :position by the key -44.

The key M is withdrawn from the fixture which is then ready for use.

When the luminaire described above is one of a number of luminaires illuminating a room and connected in parallel in a circuit controlled by a single wall switch it is not necessary, as heretofore, to open-circuit the switch and put out all the lamps in the luminaires when work of a nature making desirable an electrically uncharged fixture is to be done on one of the fixtures. The fixture to be worked on is automatically disconnected from the circuit by pulling it down to the level where the work is to be done. The other luminaires thus may be left operating to illuminate the room while work is being done on the lowered fixture.

The lighting equipment shown in Fig. 8 of the drawing is similar to that shown in Figs. 1 to 6 except that the counter-balances 9 are inverted from the position shown in Figs 1 to 6 and are mounted in the support channel 4' of the fixture I with the ends of tapes 3 attached to the support plate 6. This has the advantage of reducing the depth of the canopy and the luminaire to a minimum.

As shown, the balances 9 are fastened to the top wall I8 of the fixture l by metal straps 59 which rest against the support plate'6 when the fixture l is completely raised. The tapes 3 pass through openings in the support plate 6 and the eyes 58 are bolted to said plate. A catch I9 similar to that described in connection with the embodiment shown in Figs. 1 to 6 is mounted on the top wall l8 of the channel 4 and engages with the support plate 6. The stem 60 of the catch is longer than that of the catch of the other embodiment due to the greater separation between the top wall l8 of the channel and the plate 6 but is otherwise of the same construction. The electrical contacts GI and 62 for connecting the lamp ballast (not shown) in channel 4 to the power source are of shorter length than those of the embodiment of Figs. 1 to 6 and the female contact BI is bolted to the support plate 6 instead of a spreader. The female contact 6| comprises a metal part 63 having a cavity for accommodating the contact rod 65 of the male contact 62, an electrically insulating support 64 for the metal part 63 and a contact screw 61 passing through the insulating part 64 and engaging the metal part 63. The insulating part 66 of the male contact 62 has a shoulder 69 which rests against the outer surface of the top wall I 8 of the channel and its screw threaded end which passes through an opening in the top wall is engaged by a nut 10 which holds the contact 62 on the channel. The metal rod 65 of the contact =62 is secured to the insulating part 68 by a pair of nuts 1| and 12 engaging the screw threaded portions of the rod 65 which also has a screw 13 for engaging the ballast equipment lead wire. An insulating cap 14 covers the exposed end of the metal rod 65. Another pair of contacts is similarly mounted on plate 6 and the wall l8 alongside of contacts 6| and 62 so that the two pairs of contacts are in a line transverse to the channel 4.

The plate 6 is supported by stems 15 which are attached to a spreader (not shown) which is of the same type and attached to the ceiling stud in the same manner as the spreader 8 of the embodiment of Figs. 1 to 7. The spreader is concealed by a conventional ceiling canopy (not shown). The stems 15 may be elongated when the room has a high ceiling so that support plate 6 and the fixture, when raised, may be located at preferred distances above the working surface. A cover 76 for the support plate opens downwardly and is attached to the support plate by studs and knurled nuts 11. The open mouth of the cover 16 is separated only slightly from the fixture and is concealed thereby when the fixture is raised completely.

The fixture is raised and lowered by the same means and in the same manner and the various parts of the luminaire cooperate in the same Way as in the embodiment of Figs. 1 to 6.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A luminaire comprising in combination, a mounting plate attachable to a ceiling member, a lamp accommodating fixture mounted beneath said plate, extensible counterbalancing means connecting said plate and said fixture for supporting the latter in a raised position suitable for illumination and in a lowered position suitable for servicing, and separable contacts for connecting said fixture to an electric power source in its raised position and for disconnecting said fixture from the power source When the fixture is moved from its raised position, and a catch releasable from below said fixture, mounted on said fixture and engageable with said mounting plate for locking said fixture in its raised position, said catch being rotatable and having surfaces partly helicoidal and partly planar in shape to draw up and retain the fixture in its raised position and having also a vertically disposed stem, and a tubular guide mounted in alignment with and below said stem to guide a key into engagement with the stem, said guide having an indexing slot extending first vertically and then horizontally for engaging said key as it is moved upward and then rotated to first engage and then move the catch from its locked to its unlocked position whereby the fixture may be lowered by moving the key downwardly.

2. A luminaire comprising in combination, a mounting plate attachable to a ceiling member, a fluorescent lamp accommodating fixture mounted beneath said plate, extensible counterbalancing means connecting said plate and said fixture for supporting the latter in a raised position suitable for illumination and in a lowered position suitable for servicing, and separable contacts for connecting said fixture to an electric power source in its raised position and for disconnecting said fixture from the power source when the fixture is moved from its raised position, and a key actuated lock secured to said fixture and comprising a rotatable mounting-plate-engaging catch having a vertically disposed stem, and a tubular guide fixedly mounted in alignment with and below the stem to guide a key having an indexing pin upward into an engagement with the stem, said guide having an indexing slot the sides of which are vertical in part and horizontal in part and engage the indexing pin as the key is moved upward along the guide into engagement with the stem and then rotated in the guide to move the catch from its locked to its unlocked position whereby the fixture may be lowered by moving the key downwardly.

3. A key actuated lock for releasably engaging a lighting fixture with a support beneath which said fixture is mounted for vertical movement, said lock being mountable on said fixture and comprising a fixture support engaging, rotatable catch having a vertically disposed stem, and a tubular guide fixedly mounted in alignment with aeeasss and below the stem to guide a key having .an indexin pin upward-into an engagement with the stem, said guide having an indexing 'slot the sides of which are vertical in part and horizontal in part and engage the indexing pin as the key is moved upward along the guide into engagement with the stem and then rotated in the guide to move the catch from its locked to its unlocked position whereby the fixture may be lowered by moving the key downwardly.

4. A key actuated lock for releasably engaging a lighting fixture with a support beneath which said fixture is mounted fOr vertical movement, said lock being mountable on said fixture and comprising a rotatable catch having surfaces partly helicoidal and partly planar in shape to engage, draw up and retain the fixture against said support and having also a vertically disposed stem, said lock also comprising a tubular guide fixedly mounted in alignment with and below the stem to guide a key having an indexing pin up- Ward into an engagement with the stem, said guide having an indexing slot the sides of which are vertical in part and horizontal in part and engage the indexing pin as the key is moved upward along the guide into engagement with the stem and then rotated in the guideto move the catch from its locked to its unlocked position whereby the fixture may be lowered by movin the key downwardly.

WILLIAM G. HARLEY.

.REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

